For those who don't know procmail, here is a sample config for just the IETF-announce list. I think this is what Harald is talking about. Change the flags if you need locking. YMMV.
MAILDIR=YOUR-HOME-DIRECTORY-HERE :0 * ^To.*IETF-Announce.* * ^Subject:.*Last Call:.* last_calls :0 * ^To.*IETF-Announce.* * ^Subject: WG Review:.* wg_reviews :0 * ^To.*IETF-Announce.* * ^Subject: I-D ACTION:.* internet-drafts :0 * ^To.*IETF-Announce.* other-stuff
